(a) When the testimony or other information is to be presented to a grand jury, the order to the witness to testify or produce other information must be issued by the presiding or convening superior court judge, upon application of the district attorney. The order of a superior court judge under this section must be in writing and filed as a part of the permanent records of the court.
(b) The application may be made when the district attorney has been informed by the foreman of the grand jury that the witness has asserted his privilege against self-incrimination and the district attorney determines that the testimony or other information is necessary to the public interest. Before making application to the judge, the district attorney must inform the Attorney General, or a deputy or assistant attorney general designated by him, of the circumstances and his intent to make an application. (1973, c. 1286, s. 1; 1975, c. 166, s. 27.)